package com.equipment.training.web.utils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * 远程客户端IP
 * <p/>
 * Created by roach on 15/12/4.
 */
public class RemoteClientIpUtils {

    public static String getRemoteIP(HttpServletRequest request) {
        try {
            String ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if ("127.0.0.1".equals(ipAddress) || "0:0:0:0:0:0:0:1".equals(ipAddress)) {
                    try {
                        //根据网卡取本机配置的IP
                        InetAddress inet = InetAddress.getLocalHost();
                        ipAddress = inet.getHostAddress();
                    } catch (UnknownHostException e) {
                        ipAddress = "127.0.0.1";
                    }
                }
            }
            //对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) { //"***.***.***.***".length() = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
            return ipAddress;
        } catch (Exception e) {

        }
        return null;

    }
}